As the U.S. death toll from the novel coronavirus prepares to eclipse 200,000, President Trump on Monday incorrectly claimed at a campaign rally that covid-19 “affects virtually nobody” younger than 18, again downplaying the extent of the pandemic and contradicting his previous statements that the virus poses a risk to “plenty of young people.”

In front of a crowd of mostly maskless supporters not adhering to social distancing in Swanton, Ohio, Trump suggested that only older Americans with heart problems and preexisting conditions truly need to fear the virus.

“It affects elderly people, elderly people with heart problems and other problems. That’s what it really affects,” the president said. “In some states, thousands of people — nobody young. Below the age of 18, like, nobody. They have a strong immune system, who knows? Take your hat off to the young, because they have a hell of an immune system. But it affects virtually nobody. It’s an amazing thing.”

Trump’s sentiments go against the guidance of most public health experts and what he told Washington Post associate editor Bob Woodward in an interview in March. In one of the president’s interviews with Woodward for the book “Rage,” Trump acknowledged downplaying the severity of covid-19, saying that the virus affected “plenty of young people.”

“Now it’s turning out it’s not just old people, Bob,” Trump told Woodward. “But just today, and yesterday, some startling facts came out. It’s not just old, older.”

Much remains unknown about the virus’s effect on young people, but public health agencies have made clear that individuals younger than 18 are at greater risk of falling ill and spreading covid-19 than originally thought. Last month, the Centers for Disease Control and Prevention said the number and rate of coronavirus cases among children younger than 18 had increased “steadily” from March to July. The agency emphasized that while covid-19 remains more serious and prevalent among adults, a lack of widespread testing prevents public health experts from understanding the true incidence of infection for American children. A CDC study found that young people of color, much like their older counterparts, have been disproportionately hospitalized from covid-19, compared with their White peers.

The World Health Organization warned in August that young people are becoming primary spreaders of the virus in many countries. Several American studies published over the summer suggested that those younger than 18, with their high rate of infection and viral loads, play a much larger role in community spread of the coronavirus than researchers previously believed. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, recently said that the long-term effects of covid-19 in young people — residual symptoms such as a high rate of cardiovascular abnormalities — are “really troublesome.”

The increased risk of spread among children has taken center stage in the debate over in-person learning, as K-12 schools across the nation that had reopened have had to close or change course after students or staff members fell ill or were forced to quarantine. On Monday, Trump repeated his wish for educators to reopen in-person learning, saying, “Open your schools; everybody, open your schools.”

Reports of Americans younger than 18 dying after contracting the coronavirus have become more regular in recent months, whether it’s a 17-year-old in Florida or a 2-month-old in Michigan. “We are seeing young people who are dying from this virus,” said Maria Van Kerkhove, head of the WHO’s emerging disease and zoonosis unit, at a news conference last month.

Before Trump spoke in Swanton and promised to “end the pandemic” if he’s reelected in November, many of the president’s supporters jeered Ohio Lt. Gov. Jon Husted (R) for suggesting they cover their faces. When Husted promoted Trump-branded masks for purchase, the crowd heartily booed the lieutenant governor.

“All right, I get it,” Husted said. “But if you go in a grocery store where you gotta wear one. … Just listen up!”

Husted was booed more before getting out his final selling point to the anti-mask crowd: “But if somebody tells you to take it off, you can at least say you’re trying to save the country by wearing one of President Donald Trump’s masks.”

Felicia Sonmez and Anne Gearan contributed to this report.